Cerebral venous thrombosis presenting with subarachnoid hemorrhage after spinal anesthesia

A 22-year-old male had a meniscopathy operation using spinal anesthesia. After the operation, the patient reported a throbbing headache. His brain computed tomography (CT) showed subarachnoid hemorrhage (SAH) and hyperdense dural venous sinuses suspicious for thrombosis. Filling defects were observed in the superior sagittal and right transverse sinuses on the contrast-enhanced magnetic resonance images. The patient was diagnosed with cerebral venous sinus thrombosis (CVST). On the tenth day of his admission, his clinical findings progressed and heparin therapy was initiated after resorption of hemorrhage was observed in a second non-contrast CT scan. The patient developed decreased consciousness the day after heparin administration. A subsequent brain CT revealed intraparenchymal hemorrhage in the right anteroinferior frontal region. Heparin therapy was discontinued, and anti-edema therapy was started. The presentation of CVST with SAH is a rare condition. Furthermore, development of CVST after spinal anesthesia is very rare. In this case, CVST developed after spinal anesthesia, and its first clinical presentation was SAH. To our knowledge, this is the first case CVST presenting with SAH after spinal anesthesia.     

A case of cerebral deep venous and venous sinus thromboses with anti-cardiolipin antibody]

We describe a case of cerebral deep venous and venous sinus thromboses with anti-cardiolipin antibody. A 62-year-old male with no previous illness of thrombosis but with alcohol abuse was admitted with acute onset unconsciousness. He recovered two days after with no severe sequela. Laboratory findings suggested the preceding conditions of dehydration and inflammation. X-ray CT of the head revealed symmetrical low density areas in the thalami and basal ganglia, high density signs in the cerebral deep veins, and dilation of the lateral ventricles. MRI on the second hospital day showed abnormal intensities in the thalami and basal ganglia (high signal on T 2-weighed and FLAIR image, low signals on T 1-weighed image, but almost isointensity on diffusion weighed image) and acute to subacute phase thrombus in the superior sagittal sinus. Abnormal intensities observed on MRI disappeared gradually in the following studies. Venous phase images of cerebral angiography performed in chronic phase disclosed occlusion of the superior sagittal sinus and stenosis of the vein of Galen. These radiological findings support the diagnosis of cerebral deep vein and venous sinus thromboses. Hematological examination revealed positive anti-cardiolipin IgG antibody. Several cases of cerebral deep venous thrombosis with anti-cardiolipin antibody have been reported. In our case, dehydration induced by alcohol abuse would have been the trigger of thrombosis, while the existence of anti-cardiolipin antibody might contribute to the risk of thrombosis as an underlying condition.     

A case of deep cerebral venous thrombosis with sudden convulsion after delivery]

A 25-year-old woman was admitted to our hospital because of convulsions after delivering a baby. Her neurological examination revealed a disturbance of consciousness and weakness in both arms. A brain magnetic resonance imaging scan (MRI) showed thrombosis of the left transverse sinus and many patchy high signals at bilateral basal ganglia and subcortical areas. A digital subtraction angiogram (DSA) of the brain revealed a defect at the left transverse sinus, congestion of the cerebral venous flow at the vein of Galen and vasospastic changes at both posterior cerebral arteries. After treating the patient with a venous infusion of heparin, nicardipine and phenytoin, her neurological deficits improved within a day. When MRI and DSA were repeated 2 weeks later, the abnormal lesions had disappeared. These findings suggest that venous thrombosis and vasospasm had the pathogenesis of eclampsia in this case.     

A case of pseudotumor cerebri associated with colon cancer

A case of pseudotumor cerebri associated with iron deficiency anemia due to colon cancer is reported in a 37-year-old woman. Her initial symptoms were vomiting and severe headache. On physical examination, no lymph nodes and abdominal mass were palpable but marked anemia was noted in her skin and conjunctiva . Neurological examination revealed papilledema in her both eyes and stiff neck. There was no abnormal findings on CT scan on admission. Spinal puncture revealed CSF pressure as high as 620 mmH2O with normal cells, protein, sugar and chloride levels. Hematological examination revealed iron deficiency anemia and thrombocytosis. Angiography at third day revealed no sinus occlusion, but retention of contrast media was seen on the cortical vein of parietal lobe and right transverse sinus. Brain scintigram at sixth day revealed mild accumulation in left parietal lobe, so small venous infarction was suggested. There were two circumscribed stenotic lesions of right ascending colon in the barium enema, and right hemicolectomy was achieved. The pathological diagnosis was adenocarcinoma. The symptoms of pseudotumor cerebri was completely disappeared soon after the surgery together with resolution of anemia. She lives with no deficits now 1 year 3 months after surgery. In conclusion much attention is necessary to a patient of pseudotumor cerebri with iron deficiency anemia for the presence of cancer, because not only this central nervous system lesion is reversible and curable but also the cancer itself may be curable by surgery.     

Unilateral decompressive craniectomy in left transverse and sigmoid sinus thrombosis

Cerebral venous and dural sinus thrombosis is a rare cause of stroke. We explore the controversial issue of anticoagulation therapy and indication for decompressive craniectomy in association with severe sinus thrombosis. The 62-year-old female patient was admitted to hospital, because of first generalized seizure. A computed tomographic (CT) scan of the brain revealed a left occipital hemorrhage. Digital subtraction angiogram showing thrombosis of the left transverse and sigmoid sinus. An intravenously administered regimen of heparin was begun, because of a protein S deficiency. On the 6th day the patients level of consciousness deteriorated, necessitating intubation, hyperventilation, and mannitol. Repeat CT scan revealed increasing edema with midline shift and obliteration of the basal cisterns, although the hemorrhagic lesion was unchanged. The patient developed signs of diencephalic dysfunction. A large left temporoparietooccipital craniectomy was performed and the dura was opened. The multiloculated intraparenchymatous hemorrhage portion of the brain was not removed. In addition, the patient was treated postoperatively with heparin therapy for three months, than a regimen of phenprocoumon was begun. Twelve months later the hemianopsia had not improved and she had an incomplete Wernicke's dysphasia. When, despite adequate anticoagulation therapy and intensive care, neurological deterioration occurs in sigmoideus and/or transversus dural sinus thrombosis with unilateral edema, a decompressive craniectomy should be considered especially in young patients.     

Overlooked early CT signs of cerebral venous thrombosis with lethal outcome

The aim of this report is to emphasize the consequences of overlooked initial CT signs of cerebral venous thrombosis. Brain CT was ordered in an afebrile patient with neck pain and occipital headache. Since no abnormalities were noted on non-contrast CT study, the patient was discharged with recommendation for routine laboratory tests and plain X-ray of the cervical spine. Right hemiparesis developed the next day with persistent headache and the patient was sent back to the Neurology Clinic where he developed myoclonic seizures compatible with focal motor status epilepticus. Neuroimaging, performed two days later, revealed a huge hemorrhagic venous infarcts in the left posterior cerebral hemisphere associated with typical signs of dural sinus thrombosis. Subtle curvilinear hyperdensities were detected within the left parietal cortico-subcortical border zone on reevaluation of the initial brain CT. A posteriori these were thought to be compatible with a developing venous infarct, associated with subtle signs most consistent with combined cortical vein and sinus thrombosis. No improvement was noted after administration of anticoagulant treatment and the patient died 11 days after the initial CT scan. Detection of early CT signs of cerebral venous thrombosis is extremely important, since delaying adequate treatment may have catastrophic consequences.     

A case of Beh?et disease with transverse sinus thrombosis and successful treatment with colchicine

A 64-year-old man was admitted to our hospital because of headache and fever. Four months before admission, he had suffered from thrombophlebitis of the legs, erythema, oral aphtha and genital ulcers, and was diagnosed as having Beh?et disease. Several days prior to admission he developed fever and was treated with enoxacine, which caused disorientation and abnormal behavior. These psychiatric symptoms disappeared after enoxacine was discontinued. On admission he was neurologically normal. Fever and headache disappeared spontaneously. However, he complained again of headache, and was suspected to have cerebral sinus thrombosis. Brain CT scan showed no abnormality, but brain MRI and cerebral angiography demonstrated right transverse sinus thrombosis and stasis. He was treated with colchicine, isosorbide, and ticlopidine. Because he had a gastric ulcer, corticosteroids were not indicated. Two months later, brain MRI demonstrated reduction of the size of the sinus thrombosis, and the clinical outcome was favorable. We would like to emphasize the usefulness of MRI and colchicine in the patient with Beh?et disease complicated by sinus thromboses.     

Cerebral venous thrombosis with familial antithrombin III deficiency

A case of cerebral venous thrombosis with familial antithrombin III (AT III) deficiency was reported and we discussed the anticoagulant therapy of cerebral venous thrombosis from the viewpoint of AT III. The patient, a 17-year-old boy, was admitted to our clinic with severe bifrontal headache, generalized convulsions and progressive disturbance of consciousness. He developed deep vein thrombosis in his right leg and pulmonary emboli two years earlier when he was placed on heparin and so forth, followed by warfarin sodium. Warfarin was terminated 9 months prior to his recent illness. On neurological examination on admission, he was semicomatous with blurred disc margins, roving eye movements with right abducens nerve palsy, nuchal stiffness and right flaccid hemiplegia. Left carotid angiogram and CT scan revealed extensive superior sagittal sinus thrombosis, complicated with hemorrhagic infarcts in bilateral frontal lobes. When examined for coagulation studies, the patient and his father had decrease in AT III activity and antigen levels. He was treated successfully with antiedematous agents and anticonvulsants during acute phase of illness. He was thereafter placed on warfarin 5-6 mg/day with no further clinical thromboembolic event for 2 years 9 months. There was no neurological abnormality when he was last examined, although he was treated with valproic acid 1,200 mg/day and phenytoin 250 mg/day to control occasional adversive seizures. A coagulation study following infusion of 5,000 units of AT III was carried out. Warfarin was discontinued the day before the study. 0.64 U/kg of AT III administration resulted in a 1% increase in AT III level after the infusion. The biological half life of AT III was 14.4 hours.(ABSTRACT TRUNCATED AT 250 WORDS)     

An autopsy case of primary cerebellar-pontine angle epidermoid carcinoma]

A 65-year-old man developed right facial palsy and six months later experienced sudden unconsciousness and right hemiplegia. On admission he had severe nuchal rigidity, decreased visual acuity, and a hearing disturbance. A CT scan and angiography failed to reveal any lesions in the brain, but CSF cytology showed undifferentiated malignant cells with a high level of neuron-specific enolase. A postcontrast CT scan and MRI demonstrated diffuse meningeal enhancement and a faintly rim-enhanced cystic lesion at the cerebellopontine angle. The patient died four months after admission, and postmortem examination revealed meningeal dissemination of squamous cell carcinoma, probably arising from an epidermoid cyst at the cerebellopontine angle. Microscopic examination revealed squamous epithelial debris and a foreign body reaction in portions of the cyst wall and in the surrounding subarachnoid space near the base of the cyst. Rim enhancement of the cyst on MRI and the microscopic findings indicated that the recurrent headaches may have been the result of chemical aseptic meningitis caused by spontaneous leakage of the cyst's contents.     

A case of dural arteriovenous malformation with bilateral thalamic infarction

A 59-year-old man was admitted because of frequent vomiting and obtundation in February 1982. Neurological examination on admission revealed only slight impairment of consciousness. Papilledema, meningeal irritation sign and paralysis were not elicited. The plain CT scan was normal, but the CT scan with contrast material showed patchy enhancement in the left temporal lobe and around the third ventricle. Cerebral angiography showed a dural arteriovenous malformation (dural AVM) in the left transverse sinus fed by the left occipital artery, and the retrograde flow into the straight sinus. By the third day following admission, the level of consciousness became alert. The patient did not complain of headache, bruit and visual disturbance. He showed mild disorientation and memory disturbance. But his ordinary daily-living was independent. In August 1982, the patient gradually became inactive and apathetic. At times he lay in bed with moving his eyes, swallowing foods. At other times, he lay in bed with closing his eyes, immobile, and unresponsive except to strong painful stimuli. The patient was incontinent and required nursing care. During three month periods, the patient progressively became somnolent, speechless and immobile. Eventually, he was in a state of akinetic mutism. The patient became unresponsive. The state of consciousness fluctuated within a narrow range. The pupils were isocoric and did not react to light. He sometimes moved his eyes horizontally, but the vertical eye movement was limited. Deep tendon reflexes were hyperactive with Babinski reflex bilaterally. Passive mobilization of extremities revealed hypertonic. The CT scan disclosed the bilateral symmetrical infarction of the thalamus.(ABSTRACT TRUNCATED AT 250 WORDS)     

A case of basilar artery occlusion successfully treated with tissue plasminogen activator]

This case concerns a stroke in the basilar artery territory that was successfully treated with a tissue plasminogen activator (t-PA). A 44-year-old man suddenly lost consciousness. It took fifty minutes to arrive to our hospital after the onset. On admission, his consciousness was in a coma state. A head CT revealed normal findings but a cerebral angiography showed complete occlusion in the basilar artery. We gave 240,000 units t-PA intravenously for 60 minutes. The intravenous t-PA dramatically improved his state of consciousness. After treatment, the brain CT scan showed low-density areas in the left occipital area and right pons. The cerebral angiography showed arterial sclerosis in the basilar artery. There was no parenchymal hemorrhage or hemorrhagic infarction in the patient. The hitherto reports showed the intravenous infusion of t-PA may be particular value in patients with thromboembolic occlusion in the middle cerebral artery. In contrast, our results support its efficacy in strokes in the basilar artery territory.     

Acute aortic dissection mimicking basilar artery occlusion in a patient presenting with sudden coma

A 77-year-old female suddenly became comatose. Examination at the emergency room revealed stable vital signs and bilateral positive plantar reflexes but absent brainstem reflexes. Basilar artery occlusion was initially diagnosed and recombinant tissue plasminogen activator was administered. However, her blood pressure dropped after thrombolysis. A chest CT scan showed aortic dissection extending to the bilateral common carotid arteries. Her follow-up brain CT scan disclosed infarctions over bilateral carotid territories without brainstem involvement. Aortic dissection should be listed as a possible diagnosis in a patient who presents with a sudden coma mimicking basilar artery occlusion. Detailed clinical examination and discussion might lead to the correct diagnosis and avoid inadvertent thrombolysis in the emergency room.     

A case of angiotropic lymphoma diagnosed by adrenal biopsy]

We reported the first case of angiotropic lymphoma diagnosed by adrenal biopsy in Japan. Immunohistochemical study and southern blot hybridization analysis proved it to be B-lymphocyte origin. A 61-year-old man with history of mild hypertension and diabetes mellitus was admitted to our department because of recurrent minor stroke. On admission, general physical findings were normal. Laboratory investigations showed an elevated erythrocyte sedimentation rate and increased serum lactic dehydrogenase (LDH) level. The serial computed tomographic (CT) scan of the brain showed multifocal abnormal density lesions in bilateral hemispheres. Magnetic resonance imaging (MRI) of the brain demonstrated multiple lesions of increased signal intensity in the brainstem and bilateral hemispheres. A subsequent CT scan of the abdomen revealed swelling of bilateral adrenal glands. Adrenal biopsy was performed. Biopsy samples showed the intravascular proliferation of malignant lymphoma cells, non-Hodgkin, diffuse large cell type. These cells had the immunophenotype of a B cell lymphoma (reactive with the antileukocyte common antigen, anti-MB-1, anti-MB-2 and anti-MX-pan B, and unreactive with the anti-MT-1, anti-UCHL, anti-Ki, anti-kappa, anti-lambda and antifactor-VIII). Southern blot hybridization analysis showed monoclonal rearrangements of the immunoglobulin heavy-chain gene, which strongly suggested a B-lymphocyte origin. Thus, a diagnosis of angiotropic lymphoma was made. As soon as chemotherapy was begun, the patient fell into deep coma. A repeat CT scan of the brain was normal. His clinical status gradually deteriorated, and he died 18 months after his initial symptom. Autopsy, which was limited to the body, revealed characteristic systemic intravascular stagnation of lymphoma cells.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cerebral venous sinus thrombosis complicated with acute development of dural arteriovenous fistula: A case report

Development of dural arteriovenous fistula (dAVF) after cerebral venous sinus thrombosis (CVST) was very uncommon and for all these reported cases, the dAVF was a chronic complication. We present a case of acute development of dAVF after CVST. A 40-year-old female was admitted into our department with 2 day’s headache and vomiting for 9 h. Head computed tomography (CT) scan showed only scattered minor hematomas over the right frontal lobe. Blood test indicated an elevated D-dimer. The patient experienced transient paralysis (Todd’s paralysis) after intermittent focal epilepsy from day 3, which progressed into sustained epilepsy on day 6. Magnetic resonance imaging (MRI) on day 7 confirmed the thrombosis of the superior sagittal sinus and a large area of infarction and edema in the left frontal and parietal lobe. She was then treated with heparin and warfarin. Cerebral angiography on day 9 demonstrated a dAVF which was classified as Borden Type II and fed by the left occipital artery. Subsequently, endovascular occlusion of the fistula was conducted and the patient recovered well with only slight right limbs weakness at 1 year follow up.     

Cardiac myxoma metastatic to the brain

A case of cardiac myxoma presenting as metastatic brain tumor are reported. The patient was a 44-year-old man. One year prior to this admission, he had suffered stroke, which was characterized by right hemiparesis and dysarthria. The computed tomographic (= CT) scan of the head at that time showed a low density on the left basal ganglia and the echocardiogram suggested a left atrial myxoma. At surgery, a polypoid myxoma attached to the atrial septum was totally removed. Right hemiparesis was improved and the patient was discharged. A few months later, the patient was evaluated for multiple cutaneous masses and diagnosed by biopsy as metastatic myxoma. The patient's condition remained unchanged until this admission. In March 1985, the patient had a tonic-clonic convulsion marching from right hand and developed right hemiplegia with drowsy. An echocardiogram failed to reveal recurrence of the cardiac myxoma. A CT scan revealed a 5-cm, relatively circumscribed, low density mass in the left fronto-parietal lobe, ring mottled enhancement after contrast administration and more enhancement in the delayed scanning of 45 min. Craniotomy showed a tender, friable tumor with a yellowish cyst fluid, but apparently not invading the brain parenchyma. After complete excision of the mass, there was rapid lessing in the hemiplegia and improvement in the level of consciousness. A contrast-enhancement CT scan performed 2 weeks after craniotomy revealed no evidence of residual tumor. Pathohistological examination showed spindle-shaped and stellate cells which formed clusters and contained large amounts of acid polysaccharides as demonstrated by the alcian blue method.(ABSTRACT TRUNCATED AT 250 WORDS)     

Circulatory disturbance of deep cerebral veins in eclampsia

A case of eclampsia with interesting angiographic findings is reported. A 19-year-old woman in the 35th week of gestation by date was admitted due to a sudden onset of generalized clonic convulsion and disturbance of consciousness. The diagnosis was eclampsia. On the second hospital day, extraction of a stillborn female was performed by laminaria. Thereafter, the consciousness improved rapidly and she became alert on the following day. She was discharged without neurological deficit on the 18th hospital day. A CT scan on the day of admission showed narrow lateral ventricles and symmetrical low-density lesions in and around the basal ganglia. These had almost disappeared by the 10th hospital day. Carotid angiography on admission revealed no abnormality in the arterial phase including the lenticulostriate arteries, but, early appearance of deep cerebral veins and some cortical veins was noted. These deep veins, however, were not distinct even in the venous phase. These angiographic findings suggested medullary dilatation caused by circulatory disturbance of the deep cerebral veins. Most authors have stressed the contribution of diffuse arterial vasospasm in the pathogenesis of eclampsia in relation to low-density lesions on CT scans. In the present case, we could not find vasospasm but found circulatory disturbance of the deep cerebral veins. These angiographic findings suggested that the appearance of the low-density lesions on the CT scan was most likely due to venous congestion caused by circulatory disturbance of the deep cerebral veins, since most of the deep medullary veins in the low-density lesions flowed into the deep cerebral veins.(ABSTRACT TRUNCATED AT 250 WORDS)     

上矢状窦血栓形成早期大脑灰质CT特殊表现(附1例报道及文献复习)

目的分析上矢状窦血栓形成的早期大脑灰质CT特点,提高对上矢状窦血栓形成早期大脑灰质CT特点的认识。方法结合文献对1例上矢状窦血栓形成患者的早期脑CT影像学特点进行分析。结果患者发病后6h行脑CT平扫显示双侧额叶皮质高密度影;第3d时脑MRIT1显示上矢状窦前部血栓形成可疑,脑FLAIR-MRI显示右侧额叶高信号及左侧额叶弧形高信号,脑MRIT1相增强扫描显示双侧额叶皮层弧线型增强,MRV显示上矢状窦前1/3处见一无信号区,周围有侧枝循环形成;治疗第6d时复查脑CT和MRI均无出血征象。结论患者早期脑CT所显示的高密度影可能是皮层静脉和毛细血管血液淤积的显示,并不全是出血,对于该征象的认识并结合病理生理过程给予的合理解释对于及时正确的认识该病具有重要意义。     

A case of intracranial malignant lymphoma with pure akinesia and repeated regression on CT scans

In a case of primary reticulum cell sarcoma in the brain, histologically verified by biopsy, the tumor regressed twice on a CT scan without radiotherapy. The systemic freezing phenomenon was seen as a main clinical symptom. The patient, a 44 year-old male, first complained of decreased livido and festinating speech. He also showed frozen gait, micrographia, a decrease in spontaneity and urinary incontinence. Four months after onset he was hospitalized. Neurological findings on admission revealed freezing of gait, writing, and speech, but there was no weakness of muscles with normal tendon reflexes, and normal muscular tone. In the CT scan on admission, there were high density areas mainly in the head of the right caudate nucleus, the medial deep portion of the right frontal lobe, the right side of the hypothalamus, the anterior thalamus, the globus pallidus. There were also nodular-type enhanced effects in the same areas. Regression of the tumor was seen on the CT scans after administration of betamethasone. The tumor which had again increased in size regressed spontaneously without the use of steroids after 3 months. Thereafter, the tumor gradually became larger and an open biopsy was performed. Histopathological findings showed a reticulum cell sarcoma. There were no findings of systemic malignant lymphoma. Such intracranial malignant lymphomas showing repeated regression including spontaneous one are very rare in the literature. The freezing phenomenon in this case started with festinating speech and spread to writing and gait. L-DOPA had no effect.(ABSTRACT TRUNCATED AT 250 WORDS)     

Sequential magnetic resonance images of a case of cerebral sinus thrombosis--imaging of the thrombosed sinus and its recanalization

Magnetic resonance images of a case of superior sagittal sinus thrombosis before and after complete recanalization are presented. The patient was a 61-year-old man with two days history of intermittent right hemiconvulsion followed by post-ictal hemiplegia. Mild erythrocytosis was noted on admission. CT scans revealed left frontal hemorrhagic infarction with empty delta sign in the middle portion of the superior sagittal sinus. Left carotid angiogram showed occlusion of two frontal cortical veins and retrograde filling of these veins into the cavernous sinus. Lack of filling of the middle and anterior part of the superior sagittal sinus was noted. These studies led to the diagnosis of superior sagittal sinus thrombosis associated with hemorrhagic infarction. He was treated with intravenous infusion of low molecular dextran and venesection. Neither heparin, urokinase, hyperosmolar solutions nor steroids were used because of the presence of hemorrhagic infarction and of the lack of signs of increased intracranial pressure. He completely recovered neurologically and recanalization of the superior sagittal sinus was confirmed angiographically eight weeks after the onset. Magnetic resonance images were taken with a Siemens 1.5 T Magnetom scanner using spin-echo pulse sequences. A T 1-weighted mid-sagittal magnetic resonance image ten days after the onset showed hyperintensity in the middle part of the superior sagittal sinus which corresponded to the thrombus. Both T 1 and T 2 weighted coronal images revealed a small area of hypointensity indicating the existence of residual blood flow in the superior sagittal sinus in addition to the thrombus both in the sinus and in the cortical vein.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cheiro-oral syndrome with pontine infarct--report of a case

A case of cheiro-oral syndrome presumably due to brain stem infarction was reported. A 41-year-old man suddenly experienced the numbness of the palm and the lips on the left side at 2 p. m. March 30, 1982 and was admitted to our clinic at 5 p.m. on that day. Neurological examination on admission revealed hypesthesia of the palm and the lips on the left side, but pain and temperature sensibilities were preserved. Neither astereognosia nor extinction phenomenon was there. CT scan showed no abnormal findings. At 9 p.m. his speaking became somewhat obscure and he became unable to swallow fluid. And after ten hours or so, he became quadriplegic, anarthric and lost almost all voluntary movement below the eye, while his consciousness was preserved ("Locked-in" syndrome). CT scan taken on the 9th hospital day revealed brain stem infarction. He expired on the 58 th hospital day because of the exacerbation of pneumonia. At autopsy both vertebral arteries and basilar artery were markedly sclerotic. The rostral two-thirds of the basilar artery was occluded by organized thrombus. The serial microscopic sections through the midbrain and the medulla oblongata showed extensive infarction of the basis pontis. The tegmentum pontis remained free, except that a small offshoot of the infarct reached into the medial part of the medial lemniscus.(ABSTRACT TRUNCATED AT 250 WORDS)